DataFilter
an extensible DSL for filtering data sets
Summary
DataFilter is a library for creating filters that are consistent, reusable, and easy to read. A filter is simply something that decides whether or not an element should be removed from a set. For example, we could create a DataFilter::FilterSet that is comprised of various filters and then pass an array into the filter set. The filter set will then remove elements that do not pass each of the filters.
Installation
gem install data_filter
Usage
DataFilter::FilterSet::create provides a DSL for creating a collection
of filters which can be applied to your data. The DSL is designed to be
controller friendly and will only apply filters if a parameter is specified.
If a filter doesn't do what you need then you can pass any object that responds
to #call (e.g. a lambda) to add_filter.
filter_set = DataFilter::FilterSet.create do
# Fuzzy comparison
like_filter :name, by: params[:name]
# Fuzzy comparison with custom normalization
like_filter :name, by: params[:name], normalize_regex: /[^\w\s^@^.^+^-]/
# Keyword search
keyword_filter [:gender], by: params[:gender]
# Match truthy/falsey values
truthy_filter :student, match: params[:is_student]
# Check if within range
range_filter :age, ceiling: params[:max_age]
# Check if ranges overlap
range_filter :start, :end, floor: Date.parse('2015-01-01')
# Add a custom filter
add_filter -> (user) { user if user.student || user.age > 25 }
end
data = [
User.create(name: 'Josh', age: 26, student: false, gender: :male, start: Date.parse('2007-01-01'), end: Date.parse('2013-01-01')),
User.create(name: 'Lauren', age: 25, student: true, gender: :female, start: Date.parse('2008-01-01'), end: Date.parse('2016-01-01'))
]
# By default data which doesn't match all of the filters will be filtered out
filter_set.call(data)Changelog
* v0.4.0
- Added :normalize_regex option to LikeFilter
* v0.3.1
- Extend DSL with PrefixFilter
* v0.3.0
- Added PrefixFilter
* v0.2.0
- Fix RangeOverlapFilter edge cases
License
The gem is available as open source under the terms of the MIT License.